Identification of proteolytic isozymes from Antarctic krill (Euphausia superba) in an enzymatic debrider

• 1.1. A partially purified krill extract (enzymatic debrider) intended for clinical use was electrophoretically characterized by polyacrylamide gel electrophoresis (PAGE) and by crossed immunoelectrophoresis (CIE) using polyclonal rabbit antibodies.
• 2.2. Three main types of proteolytic enzymes (serine proteinase, carboxypeptidase A and B) with mol. wts of 33,000, 28,000 and 35,000, respectively, could be separated by SDS—g-PAGE under reducing conditions.
• 3.3. Routine CIE analysis of krill samples revealed four protease-active immunoprecipitates. Two of these precipitates were associated with the proteinase activity, one with carboxypeptidase A and one with carboxypeptidase B.
• 4.4. Improving resolution of CIE by extending electrophoresis in the first dimension permitted separation of three serine proteinases of which two were isozymes (II and III) and the third one was unique (I).
• 5.5. Furthermore carboxypeptidase A could also be separated into two isozymes (AI and AII) while carboxypeptidase B still exhibited one single component.
• 6.6. Six individual immunoprecipitates were thus identified and proved to be related to the protease activity. Highly purified enzymes were used as references in CIE and tandem-CIE to establish identification of each enzyme in the krill mixture.